Psychotropics and challenging behaviour in people with an intellectual disability

To the Editor: Hilmer and Gnjidic drew attention to the pharmacological management of behavioural problems in nursing home residents, and called for a reduction in inappropriate prescribing and the development of alternative management strategies.1 We extend these concerns to another vulnerable population — people with intellectual disability. Historically, this population is one of the most medicated groups in modern society.

About 30% of people with intellectual disability have a mental illness, but up to 60% are prescribed psychotropic medication to manage challenging behaviour.2 Challenging behaviour, a catch-all term describing aggression and other socially unacceptable behaviour, can isolate individuals and cause significant distress for individuals, families, carers and clinicians. No Australian guidelines address treatment of challenging behaviour in people with intellectual disability with psychotropics, but UK guidelines recommend the use of non-pharmaceutical interventions in the absence of a diagnosable mental illness.3

Diagnosing mental illness requires clear communication, which is challenging for people with cognitive and communication impairments. Also, clinicians may feel pressure from carers to medicate. As a result, psychotropic medication — often antipsychotics — may be prescribed on a hypothesis of efficacy, rather than a diagnosis of a psychotic disorder. Corresponding improvements in challenging behaviour may then be attributed to medication, rather than sedation.

Definitive evidence of the effectiveness of antipsychotics in mitigating challenging behaviour is lacking. A seminal trial published in The Lancet found that risperidone was no more useful than placebo in reducing aggression in people with intellectual disability.4 In contrast, evidence of serious side effects associated with these medications is clear.5 People with intellectual disability face a higher burden of disease than other Australians; any decision to risk these side effects for an unproven benefit must be taken with extreme caution.

Australia lags behind the United Kingdom, where experience with intellectual disability is recognised as an essential component of training for general practitioners and psychiatrists. The Royal Australian and New Zealand College of Psychiatrists recently established a special interest group in intellectual disability; while this is a positive step, limited training in the assessment and management of people with intellectual disability continues to compromise optimal treatment. We need guidelines to reduce prescribing of psychotropics to people with intellectual disability without a diagnosis of mental illness, and research in this area is urgently needed to support the development of evidence-based care.